JP2000218245A - Vapor drying device for glass substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform drying free from the non-uniformity of drying regardless of plate thickness by providing a vapor quantity control means, in the drying of a glass substrate by supplying vapor generated by heating a solvent for cleaning to a drying vessel and controlling its inside to have a prescribed vapor density. SOLUTION: In the drying of the glass substrate used for a liquid crystal display panel or the like, a cassette 2 housing plural pieces of the glass substrate is charged into a housing 11 of a vapor drying device 10 and is supported with a supporting body. The drying of the glass substrate is performed by supplying the vapor into the housing 11 from a vapor generating device for vaporizing the solvent for cleaning such as isopropyl alcohol through a supply pipe line 17 to a duct 16, in which plural vapor supply ports 14, 15 are formed. The optimum drying condition to the thickness (heat capacity) of the glass substrate is established to prevent the non-uniformity of the drying by controlling the vapor quantity with shutters 18 as the vapor quantity controlling means of the glass substrate which are attached to the vapor supply ports 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam drying apparatus for a glass substrate, and more particularly to a steam drying apparatus suitable for drying a glass substrate used for a liquid crystal display panel after washing.

[0002]

2. Description of the Related Art In manufacturing a liquid crystal display panel,
Cleaning and drying of the glass substrate is regarded as one of the important processes from the viewpoint of improving the yield. In other words, the quality is greatly affected on the subsequent processing steps.

Usually, a glass substrate for a transparent electrode substrate is repeatedly washed with pure water a plurality of times (for example, twice), then washed in an IPA (isopropyl alcohol) solution, and further immersed in the IPA solution. Replacement with water is performed.

[0004] Then, it is sent to a drying step as a final stage of washing. CFCs were used for substrate drying before,
From the viewpoint of global environmental protection, for example, alcohol vapor drying has been adopted.

[0005] To explain this, in the alcohol drying step, a steam generator for heating IPA to generate steam and a drying tank to which steam is supplied from the steam generator are provided. Drying is performed by exposing the glass substrate to a steam atmosphere.

[0006]

The boiling point of IPA is 7
The temperature of the glass substrate after washing is 8 to 81 ° C., and the temperature of the glass substrate after washing is room temperature or lower. Therefore, when a glass substrate is placed in a drying tank, IPA is condensed on the surface of the glass substrate.

[0007] If this condensation uniformly adheres to the surface of the glass substrate, drying unevenness does not occur, but the state of condensation depends on the thickness (heat capacity) of the glass substrate. For example, when the thickness of the glass substrate is about 0.5 to 1.3 mm, even if the drying unevenness does not occur, the thickness is 0.1 to 0.1 mm in the same IPA vapor atmosphere.
It has been confirmed that when a thin glass substrate of 0.4 mm is exposed, drying unevenness occurs due to its small heat capacity.

To prevent such drying unevenness, the conditions may be changed. That is, in the case of a thin glass substrate, it is only necessary to increase the volume in the drying tank or to control the heating capacity of the steam generator to reduce the amount of steam generated. There are issues.

That is, to prepare a drying tank having a different internal volume according to the thickness of the glass substrate, a large capital investment is required, which is not preferable. Further, even if the heating capacity of the steam generator is adjusted according to the thickness of the glass substrate, it takes a long time to switch the heating capacity, and the productivity is deteriorated.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and has as its object to adjust the heating capacity of a steam generator in the same drying tank. It is another object of the present invention to provide a vapor drying apparatus for a glass substrate which can be dried from a thick plate to a thin plate without causing drying unevenness.

According to the present invention, it is an object of the present invention to provide a steam generating means for generating a steam by heating a cleaning solvent such as isopropyl alcohol (IPA); A drying tank having a steam density, wherein the glass substrate is dried by exposing the glass substrate to a steam atmosphere of the drying tank to adjust the amount of steam supplied to the drying tank. This is achieved by providing adjusting means.

According to this structure, the amount of IPA vapor supplied into the drying tank is adjusted by the amount of steam adjusting means, so that the heating capacity of the steam generator can be adjusted in the drying tank having the same internal volume. No, for example, a thickness of 0.1 to 1.3
mm glass substrate.

[0013] In the present invention, the steam amount adjusting means may be a flow rate adjusting valve provided in a pipe from the steam generating means to the drying tank, but the opening area of the steam supply port provided in the drying tank is variable. It is preferable to use a shutter plate which can be easily applied to an existing drying tank.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention;

FIG. 1 shows a steam drying apparatus 10 according to this embodiment.
FIG. 2 is a right side sectional view thereof.
FIG. 3 shows a cassette 2 used when a plurality of glass substrates 1 are stored in the steam drying apparatus 10 as one lot. According to this, the steam drying device 1
0 has a box-shaped housing 11 having an opening 111 for taking the cassette 2 in and out of the upper surface.

Although not shown, above the housing 11, the cassette 2 is inserted through the opening 111 into the housing 11.
And a cassette support that can be raised and lowered to be disposed at a lower position substantially at the center of the cassette support. Further, a condenser pipe 13 for condensing IPA vapor is provided along an inner surface of the housing at an upper portion in the housing 11.

A steam supply port 14 is formed in the lower part of the side surface of the housing 11. According to this embodiment, the steam supply ports 14 are rectangular and are provided one for each side of the housing 11.

The steam supply port 1 is also provided on the bottom of the housing 11.
5 are provided. In this embodiment, the steam supply port 15 at the bottom is a cylindrical pipe 151 projecting into the housing 11.
An umbrella 152 is placed above the cylindrical tube 151. In this embodiment, the steam supply port 15 on the bottom is 2
Six are provided in an array of × 3.

A duct 16 is provided from the side surface to the bottom surface of the housing 11 so as to cover the steam supply ports 14 and 15 on the respective surfaces. One end of the duct 16 has a steam supply pipe 17 from a steam generator (not shown).
Is connected.

In this embodiment, IPA is used as a cleaning solvent.
(Isopropyl alcohol) is used, and the vapor generation device is provided with a storage tank for IPA and an electric heater for heating the storage tank to generate IPA vapor.

Each of the steam supply ports 14 on the side face has a shutter 18 as a steam amount adjusting means for making the opening area variable.
Are provided respectively. The shutter 18 is a manual type,
Any type of electric type may be used. In addition, each shutter 1
8 may be independently adjustable, or may be linked by a link or the like so that they can be adjusted collectively.

The sliding direction of the shutter 18 is arbitrary. In this embodiment, the vertical direction is used, but the horizontal direction may be used. In some cases, instead of the slide type, a rotary type that opens and closes with a hinge or the like may be used. Further, unlike this embodiment, a shutter 18 may be provided in the steam supply port 15 on the bottom surface.

In the cassette 2, a plurality of glass substrates 1
Can be accommodated in the vertical direction. The upper and lower surfaces of the cassette 2 are open so that IPA vapor can flow therethrough, and spacer grooves 211 and 211 for holding the glass substrates 1 at predetermined intervals are formed in the opposing side frames 21 and 21 respectively. I have. Although not shown,
A stopper for preventing the glass substrate 1 from dropping is provided on the lower surface side of the cassette 2.

Here, a glass substrate having a thickness of 0.1 to 0.4 mm is used as a thin glass substrate, and a glass substrate having a thickness of 0.5 to 1.3 m is used.
When the glass substrate of m is a thick glass substrate, the steam drying device 10 can clean and dry both of them without causing drying unevenness. The vertical and horizontal dimensions of the substrate are the same in both cases. For example, in FIG. 3, the horizontal width W is 180 mm and the vertical width H is 160 (（215) mm.
And

Regardless of the thickness, the glass substrate 1 is stored in the cassette 2 a plurality of times (for example, two times).
Times) pure water washing and IPA solution washing, and further IP
After passing through a replacement step with water by immersion in liquid A, FIG.
It is put in the housing 11 as shown in FIG.

In the housing 11, the substrate is exposed to IPA vapor supplied from a vapor generator to perform washing and drying. In the case of a thick glass substrate, the opening area of the vapor supply port 14 is reduced by the shutter 18. Can be spread. This allows more IPA vapor to flow into the housing 1
1 is supplied.

On the other hand, in the case of a thin glass substrate, the opening area of the vapor supply port 14 is reduced by the shutter 18 and the amount of IPA vapor supplied into the housing 11 is reduced.

Incidentally, in this embodiment, the inner dimensions of the housing 11 are about 700 mm in height and about 500 m in width.
m, the depth is about 600 mm, and the amount of IPA vapor supplied into the housing 11 is in the range of 3 to 10 liters per minute for a thick glass substrate.

On the other hand, in the case of a thin glass substrate, the diameter is reduced to about 2 to 4 liters per minute. The time required for the washing and drying is about 2 to 4 minutes in both cases.

As described above, according to the present invention, the amount of IPA vapor can be adjusted according to the thickness (heat capacity) of the glass substrate, and the glass substrate can be dried neatly under optimum drying conditions without drying unevenness. it can.

In the above embodiment, IPA is used as a cleaning solvent, but the present invention is not limited to this. Further, a shutter 18 is used as a steam amount adjusting means.
However, in some cases, a flow control valve may be provided in the pipe 17 from the steam generator. Furthermore, the present invention is also applicable to steam drying of glass substrates other than glass substrates for liquid crystal display panels.

[0032]

As described above, according to the present invention,
In the drying tank to which steam is supplied from the steam generating means,
When exposing the glass substrate to the steam atmosphere and drying it, the amount of steam supplied to the drying tank can be adjusted, so that the heating capacity of the steam generator can be adjusted in the same drying tank, Drying can be performed from a thick plate to a thin plate without causing drying unevenness.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing an embodiment of a glass substrate steam drying apparatus according to the present invention.

FIG. 2 is a right side sectional view of the embodiment.

FIG. 3 is a perspective view showing a glass substrate cassette used in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Cassette 10 Steam drying apparatus 11 Housing 13 Condenser pipe 14, 15 Steam supply port 16 Duct 17 Steam supply pipe 18 Shutter

Continued on the front page F term (reference) 2H090 HC18 JB02 JC19 3B116 AA02 BB01 CC03 3B201 AA02 BB01 BB93 BB95 CC12 3L113 AA01 AC05 AC08 AC16 AC48 AC50 AC54 AC65 AC67 AC75 AC79 AC90 BA34 CA11 DA01 DA24

Claims (2)

[Claims] 1. A steam generating means for generating steam by heating a cleaning solvent such as isopropyl alcohol, and a drying tank supplied with steam from the steam generating means and having a predetermined steam density inside. A glass substrate steam drying apparatus for drying a glass substrate by exposing the glass substrate in a steam atmosphere of the drying tank, wherein a steam amount adjusting means for adjusting an amount of steam supplied to the drying tank is provided. Steam drying equipment for glass substrates. 2. The drying tank has a steam supply port connected to the steam generation means on at least one of a bottom surface and a side face thereof, and the steam amount adjustment means changes an opening area of the steam supply port. The steam drying apparatus for a glass substrate according to claim 1, comprising a shutter plate.